Game should supply any needed tools that are not readily available (such as for the Hardware Challenge).

In game items may be limited, so important that team members work and report back to each other.

Game should play to a storyline to make it more like an interactive fiction rather than a scavenger hunt.

No real-life characters should be in the game, aside from the players.

Concept 2

Smartphone application utilizing QR code stickers.
Game Masters (GM) can "roll their own" puzzles giving clues to where they need to look, or virtual objects they need to pick up.
GMs then print their own QR codes on stickers and hide them around town.
Users ride around town looking for the clues for the game, and scan it in using their smartphone, or take a picture of the QR code
and feed it back into a website. The phone then hits a server, acknowledges that the puzzle has been solved, and provides the next quest.